Andromeda went on sale pretty soon after release and currently goes down to about $20-30 USD. Here are some threads discussing this topic, but most users will say that the game is worth getting at the discounted price.

Do I need to play the OT before playing Andromeda?

Technically, no. However, it is generally highly recommended you do so, as playing the OT will greatly enhance your understanding of MEA.

Yes, it's really good. Nothing at all like that top-down POS that Mass Effect: Galaxy was. You can choose which upgrades and armor pieces to buy, it has an over-the-shoulder view, and it's actually kinda challenging.